package com.zmn.oms.third.base.util;

import lombok.SneakyThrows;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.SecureRandom;

/**
 * 类描述：AES数据加密和解密
 *
 * @author xiewenbing
 * @date 2020/11/04
 */

public class AESUtil {

    /**
     * 加密
     *
     * @param content  需要加密的内容
     * @param password 加密密码
     * @return 加密结果
     */
    public static String encrypt(String content, String password) {
        try {
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
            secureRandom.setSeed(password.getBytes());
            kgen.init(128, secureRandom);
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");// 创建密码器
            byte[] byteContent = content.getBytes("utf-8");
            cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
            byte[] result = cipher.doFinal(byteContent);
            return parseByte2HexStr(result); // 加密
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 解密
     *
     * @param content  待解密内容
     * @param password 解密密钥
     * @return 解密结果
     */
    @SneakyThrows
    public static String decrypt(String content, String password) {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
        secureRandom.setSeed(password.getBytes());
        kgen.init(128, secureRandom);
        SecretKey secretKey = kgen.generateKey();
        byte[] enCodeFormat = secretKey.getEncoded();
        SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");// 创建密码器
        cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
        byte[] result = cipher.doFinal(parseHexStr2Byte(content));
        return new String(result); // 加密
    }

    /**
     * 将二进制转换为十六进制
     *
     * @param buf 二进制数组
     * @return 十六进制数据
     */
    public static String parseByte2HexStr(byte[] buf) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * 将十六进制转换为二进制
     *
     * @param hexStr 十六进制数据
     * @return 二进制数组
     */
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1) {
            return null;
        }
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }
}
